Probe approach for dgs sizing

ABSTRACT

An ultrasonic detection assembly detects a characteristic in a test object. The ultrasonic detection assembly includes a phased array probe positioned in proximity to a peripheral surface of the test object. The phased array probe includes a plurality of transducer elements. The transducer elements of the phased array probe transmit a sound beam into the test object. The sound beam is movable by the phased array probe within the test object to detect the characteristic.

RELATED APPLICATION

Benefit of priority is claimed from U.S. patent application Ser. No.13/706,531, filed Dec. 6, 2012, the entire disclosure of which isincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to ultrasonic detectionassemblies, and more particularly, to ultrasonic detection assembliesincluding phased array probes.

2. Discussion of the Prior Art

Ultrasonic detection assemblies are known and used in many differentapplications. Ultrasonic detection assemblies are used, for example, toinspect a test object and to detect/identify characteristics of the testobject, such as corrosion, voids, inclusions, length, thickness, etc. Toaccurately detect the location of these characteristics within the testobject, a straight beam probe was previously used. The straight beamprobe emitted a generally straight sound beam into the test object. Awedge was used to provide for inclined sound beams from the straightbeam probe into the test object. Multiple different angles (e.g., 3.5°,7°, 10.5°, 14°, 17.5°, 21°, 24°, etc.) were required to be tested sincenot all characteristics could be detected with the straight beam probe.

Following these tests, a DGS (distance, gain, size) method was used todetermine a size of the characteristic in the test object based oncomparing an amplitude of the sound beams for the various angles. TheDGS method generally uses straight beam probes generating a rotationallysymmetric sound field in the test object. Providing multiple test runsis time consuming, leading to decreased productivity. Further, usingdifferently sized wedges for each of the specified angles (or usingmultiple probes simultaneously) is difficult, expensive, and timeconsuming.

Accordingly, it would be beneficial to provide an ultrasonic detectionassembly that allows for the transmission of sound beams at multipledifferent angles to detect characteristics within a test object.Further, it would be beneficial to be able to move the sound beams in amore precise manner without the need for wedges with specific angles(e.g., e.g., 3.5°, 7°, 10.5°, 14°, etc.).

BRIEF DESCRIPTION OF THE INVENTION

The following presents a simplified summary of the invention in order toprovide a basic understanding of some example aspects of the invention.This summary is not an extensive overview of the invention. Moreover,this summary is not intended to identify critical elements of theinvention nor delineate the scope of the invention. The sole purpose ofthe summary is to present some concepts of the invention in simplifiedform as a prelude to the more detailed description that is presentedlater.

In accordance with one aspect, an ultrasonic detection assembly fordetecting a characteristic in a test object is provided. The ultrasonicdetection assembly includes a phased array probe positioned in proximityto a peripheral surface of the test object, the phased array probeincluding a plurality of adjacent transducer elements collectivelyconfigured to provide an inspection surface extending substantiallyparallel to a direction along which the test object extends, eachtransducer being operatively configured to emit a respective beam intothe test object so as to provide a pattern of constructive interferencesuch that the phased array probe is providing a single, rotationallysymmetric sound beam into the test object, the phased array probe beingconfigured to provide for a rotational symmetry that exists over acomplete steering range of the phased array probe.

In accordance with another aspect, an ultrasonic detection assembly fordetecting a characteristic in a test object is provided. The ultrasonicdetection assembly includes a phased array probe positioned in proximityto a peripheral surface of the test object, the phased array probeincluding a plurality of adjacent transducer elements collectivelyconfigured to provide an inspection surface, each transducer beingoperatively configured to emit a respective beam into the test object soas to provide a pattern of constructive interference such that thephased array probe is providing a single, rotationally symmetric soundbeam into the test object, the phased array probe being configured tomove the sound beam within a range of angles from the phased array probeand bounded by a first beam position extending in a first direction fromthe phased array probe and a second beam position extending in a second,different direction from the phased array probe within the test objectto detect the characteristic.

In accordance with another aspect, an ultrasonic detection assembly fordetecting a characteristic in a test object is provided. The ultrasonicdetection assembly includes a phased array probe positioned in proximityto a peripheral surface of the test object, the phased array probe beingconfigured to transmit a sound beam into the test object, wherein thesound beam is movable by the phased array probe within the test objectto detect the characteristic. The phased array probe includes aplurality of transducer elements that are configured to transmit thesound beam, an inspection surface of the transducer elements configuredto extend substantially parallel to a direction along which the testobject extends.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other aspects of the present invention will becomeapparent to those skilled in the art to which the present inventionrelates upon reading the following description with reference to theaccompanying drawings, in which:

FIG. 1 is a schematic, perspective view of an example ultrasonicdetection assembly including a phased array probe detecting acharacteristic of a test object in accordance with an aspect of thepresent invention;

FIG. 2 is a side elevation view of the example ultrasonic sensorassembly that is partially torn open to show an interior portion of thetest object;

FIG. 3 is an end view of an inspection surface of the phased arrayprobe;

FIG. 4 is an end view of a second example inspection surface of thephased array probe;

FIG. 5 is a side elevation view of the example ultrasonic sensorassembly similar to FIG. 2 as the phased array probe transmits arotationally symmetric sound beam into the test object; and

FIG. 6 is a sectional view of a second example ultrasonic sensorassembly along line 6-6 of FIG. 2 including an adjustment structure forpositioning the phased array probe in proximity to the test object.

DETAILED DESCRIPTION OF THE INVENTION

Example embodiments that incorporate one or more aspects of the presentinvention are described and illustrated in the drawings. Theseillustrated examples are not intended to be a limitation on the presentinvention. For example, one or more aspects of the present invention canbe utilized in other embodiments and even other types of devices.Moreover, certain terminology is used herein for convenience only and isnot to be taken as a limitation on the present invention. Still further,in the drawings, the same reference numerals are employed fordesignating the same elements.

FIG. 1 illustrates a perspective view of an example ultrasonic detectionassembly 10 according to one aspect of the invention. The ultrasonicdetection assembly 10 is for inspection of an example test object 12having a characteristic 18 (e.g., void, inclusion, thickness, crack,corrosion, etc.). The ultrasonic detection assembly 10 includes a phasedarray probe 20 positioned in proximity to a peripheral surface 14 of thetest object 12. The phased array probe 20 can detect the characteristic18 by directing one or more rotationally symmetric (e.g., generallycircular) sound beams into the test object 12. To provide improveddetection within the test object 12, the phased array probe 20 can move(e.g., steer) the rotationally symmetric sound beams along a variety ofdirections within the test object 12.

The example test object 12 includes a tubular shaft having a generallycylindrical shape in FIG. 1. The test object 12 extends between opposingends and can include a solid body (as shown) or a non-solid body (e.g.,hollow body, pipe, or the like). It is to be appreciated that the testobject 12 is somewhat generically/schematically depicted in FIG. 1 forease of illustration. Indeed, the test object 12 can include a varietyof dimensions, such as by being longer or shorter than as shown, or byhaving a larger or smaller diameter. Further, the test object 12 is notlimited to a pipe-like structure extending along a linear axis, and mayinclude bends, undulations, curves, or the like.

The peripheral surface 14 of the test object 12 provides the generallycylindrical shape. In other examples, the test object 12 includes othernon-cylindrical shapes and sizes. For example, the test object 12 couldhave a non-circular cross-sectional shape, such as by having a square orrectangular cross-section. Still further, the test object 12 may includea tubular shape, conical shape, or the like. The test object 12 is notlimited to shafts, pipes, or the like, but instead, could include walls,planar or non-planar surfaces, etc. The test object 12 could be used ina number of applications, including inspection of parts (e.g., generatorshafts, etc.), pipeline corrosion monitoring, or the like. As such, thetest object 12 shown in FIG. 1 includes only one possible example of thetest object.

The ultrasonic detection assembly 10 further includes a controller 15.The controller 15 is somewhat generically/schematically depicted. Ingeneral, the controller 15 can include any number of differentconfigurations. In one example, the controller 15 is operativelyattached to the phased array probe 20 by means of a wire. In furtherexamples, however, the controller 15 could be in wireless communicationwith the phased array probe 20. The controller 15 can send and receiveinformation (e.g., data, control instructions, etc.) from the phasedarray probe 20 through the wire (or wirelessly). This information can berelated to characteristics of the test object 12 (e.g., corrosion, wallthickness, voids, inclusions, etc.), characteristics of sound beamstransmitted and/or received by the phased array probe 20, or the like.The controller 15 can include circuits, processors, running programs,memories, computers, power supplies, ultrasound contents, or the like.In further examples, the controller 15 includes a user interface,display, and/or other devices for allowing a user to control theultrasonic detection assembly 10.

Turning now to FIG. 2, a partially torn open side elevation view of thetest object 12 is shown. The test object 12 includes an interior portion16. The interior portion 16 is substantially solid, though in furtherexamples, the interior portion 16 could be at least partially hollowand/or include openings therein. The interior portion 16 of the testobject 12 could be formed of a number of different materials, includingmetals (e.g., steel, titanium, etc.), metal alloys, and/or non-metals(e.g., concrete, or the like). It is to be appreciated that while only aportion of the interior portion 16 of the test object 12 is shown (i.e.,the torn open portion), the remaining interior portions of the testobject 12 can be similar or identical in structure as the interiorportion 16 shown in FIG. 2.

The test object 12 can further include a characteristic 18. Thecharacteristic 18 is somewhat generically/schematically depicted, as itis to be appreciated that the characteristic 18 includes a number ofpossible structures, sizes, shapes, etc. For example, the characteristic18 includes corrosion, voids, inclusions, defects, cracks, thicknesses,etc. Further, while the characteristic 18 is generically depicted as aquadrilateral shape, the characteristic 18 could likewise includeelongated cracks/defects, non-quadrilateral shapes, or the like. It isfurther appreciated that FIG. 2 depicts one characteristic forillustrative purposes, but in further examples, the characteristic 18could likewise include a plurality of characteristics. Thecharacteristic 18 may be positioned at any location within the interiorportion 16, such as by being closer to or farther from the phased arrayprobe 20, closer to one of the ends of the test object 12, etc.

Turning to the phased array probe 20 of the ultrasonic detectionassembly 10, the phased array probe 20 is an elongate, cylindricallyshaped probe extending between opposing ends. In further examples, thephased array probe 20 is not limited to the specific structure shown inFIG. 2, and could include any number of different sizes and shapes. Thephased array probe 20 is positioned in proximity to the peripheralsurface 14 of the test object 12. In one example, the phased array probe20 is non-movably positioned in proximity to the test object 12, suchthat the phased array probe 20 is statically held, attached, etc. withrespect to the test object 12.

The phased array probe 20 includes an inspection surface 22 disposed atan end of the phased array probe 20. The inspection surface 22 can besubstantially planar (as shown), or in further examples, could includebends, curves, or the like to match the shape of the peripheral surface14. In one example, when the test object 12 has a relatively largerdiameter than a length across the inspection surface 22, the inspectionsurface 22 can be substantially planar such that the inspection surface22 is in contact with the peripheral surface 14. By being positioned inproximity to the peripheral surface 14, the inspection surface 22 ispositioned in contact with the peripheral surface 14. In anotherexample, the inspection surface 22 may be positioned in proximity to theperipheral surface 14 but may not be in contact with the peripheralsurface 14. In such an example, the inspection surface 22 may be spacedapart a distance from the peripheral surface 14 and/or may include otherstructures positioned between (and in contact with) the inspectionsurface 22 on one side and the peripheral surface 14 on an oppositeside.

Turning now to FIG. 3, an example of the inspection surface 22 of thephased array probe 20 is shown. The inspection surface 22 includes agenerally circular shape associated with a plurality of transducerelements 24. As is generally known, each of the transducer elements 24includes a piezoelectric crystal. In response to an application ofelectric current to the transducer elements 24, each of the transducerelements 24 can transmit (e.g., send, convey, etc.) a sound beam in adirection outwardly from the inspection surface 22. Likewise, each ofthe transducer elements 24 can receive a sound beam, which produces anelectrical current in response.

The transducer elements 24 associated with the inspection surface 22 arelaterally spaced apart, such as by being linearly segmented. Inparticular, the transducer elements 24 can be separated by segments 26that extend generally linearly across the inspection surface 22. Thesegments 26 extend parallel to each other, such that the transducerelements 24 are arranged to form a linear array. The segments 26 canrepresent any type of segmentation/separation between the transducerelements 24. For example, the segments 26 can represent cuts, scores, orsimilar separations manufactured into the inspection surface 22. Inanother example, the segments 26 represent a space between separatelyprovided transducer elements 24. The segments 26 can be closer togetheror farther apart, such that the transducer elements 24 could be narroweror wider, respectively.

By providing the transducer elements 24 as being linearly segmented, asound beam transmitted from the inspection surface 22 can beguided/moved. For example, each of the transducer elements 24 will emita separate sound beam. The transmission of sound beams from adjacenttransducer elements can be delayed (e.g., time shifted), such that apattern of constructive interference is formed which results in a singlesound beam being transmitted at a certain angle. Based on this delay andtime shifting, the sound beam from the transducer elements 24 caneffectively be moved/guided from the inspection surface 22 and into thetest object 12. In the shown example, the sound beam can be moved alonga two dimensional direction 27 (represented generically as anarrowhead).

Turning now to FIG. 4, a second example of an inspection surface 122 ofthe phased array probe 20 is shown. In this example, the secondinspection surface 122 includes a generally square shape, though othershapes are envisioned. The second inspection surface 122 is associatedwith a plurality of second transducer elements 124. As is generallyknown, each of the second transducer elements 124 includes apiezoelectric crystal. As set forth above, each of the second transducerelements 124 can transmit (e.g., send, convey, generate, etc.) a soundbeam in a direction outwardly from the second inspection surface 122.Likewise, each of the second transducer elements 124 can receive a soundbeam, which produces an electrical current in response.

The second transducer elements 124 associated with the second inspectionsurface 122 are arranged as a matrix. In particular, the secondinspection surface 122 includes a rectangular array of second transducerelements 124 arranged into rows and columns. In the shown example, thematrix includes an 8×8 matrix, with eight rows of second transducerelements 124 and eight columns of second transducer elements 124. Ofcourse, in further examples, the second inspection surface 122 is notlimited to including the 8×8 matrix, and could include a matrix ofnearly any size (i.e., larger or smaller than as shown). Likewise, thesecond inspection surface 122 is not limited to including therectangular array, and could include other quadrilateral shaped arrays,or even non-quadrilateral shaped arrays.

The second transducer elements 124 are separated by segments 126. Thesegments 126 can extend generally linearly from one side to an opposingsecond side of the second inspection surface 122. Further, the segments126 can have a generally consistent spacing between adjacent segments,such that the second transducer elements 124 have substantiallyidentical sizes and shapes (e.g., square shapes). Of course, in furtherexamples, the segments 126 could be oriented in any number of ways. Forexample, the segments 126 could be angled diagonally across the secondinspection surface 122, such that the second transducer elements 124include non-square shapes.

By providing the second transducer elements 124 in the form of a matrix,a sound beam transmitted from the second inspection surface 122 can berotationally symmetric. For example, a portion of the second transducerelements 124 (i.e., less than all) can be activated to emit a separatesound beam. In the shown example, active elements 124 a will emit soundbeams while inactive elements 124 b may not emit sound beams. The activeelements 124 a can form a generally circular shape, indicated as agenerally circular grouping 130. The circular grouping 130 of the activeelements 124 a can be disposed towards the center of the secondinspection surface 122. The inactive elements 124 b are disposedgenerally towards the corners of the second inspection surface 122. Inthe shown example, the active elements 124 a can include four transducerelements at a center of each side of the second inspection surface 122.However, in further examples, the circular grouping 130 could besmaller, such that fewer active elements 124 a will emit sound beams.

The active elements 124 a forming the circular grouping 130 will emitseparate sound beams. Similar to the example shown in FIG. 3, thetransmission of the sound beams from the active elements 124 a can bedelayed (e.g., time shifted), such that a pattern of constructiveinterference is formed which results in a single sound beam beingtransmitted at a certain angle. Based on this delay and time shifting,the sound beam from the active elements 124 a can effectively bemoved/guided from the second inspection surface 122 and into the testobject 12. In this example, the rotationally symmetric sound beamgenerated and transmitted by the active elements 124 a is moved along athree dimensional direction 127 (represented generically as anarrowhead). As such, the rotationally symmetric sound beam can be movedthree dimensionally within the test object 12.

It is to be appreciated that the arrowhead representing the threedimensional direction 127 includes only two perpendicular lines (e.g.,first line pointing up/down and second line pointing side to side).However, the movement of the sound beam is not so limited to movingalong these directions (e.g., up, down, left, right). Rather, the threedimensional movement of the sound beam includes directions other thanthose represented with the arrowhead, such as by moving in an angleddirection with respect to the perpendicular lines. Indeed, the arrowheadrepresenting the three dimensional direction 127 is merely intended toshow that the sound beam emanating from the second inspection surface122 is not limited to the two dimensional direction 27 of FIG. 3.

Turning now to FIG. 5, the operation of detecting the characteristic inthe test object 12 with the ultrasonic detection assembly 10 will now bedescribed. As shown, the phased array probe 20 is positioned inproximity to the test object 12. In particular, the inspection surface22 (or the second inspection surface 122) of the phased array probe 20is in contact with the peripheral surface 14 of the test object 12. Thetest object 12 includes the characteristic 18 positioned within theinterior portion 16.

Initially, the phased array probe 20 will generate and transmit a soundbeam 50 into the test object 12. The sound beam 50 can include therotationally symmetric sound beam described above with respect to FIG. 3or 4. In particular, the phased array probe 20 in FIG. 5 can includeeither of the inspection surface 22 (FIG. 3) or the second inspectionsurface (FIG. 4).

The sound beam 50 can initially be in a first sound beam position 50 a.The first sound beam position 50 a can extend at an angle with respectto the inspection surface 22 into the interior portion 16. It is to beappreciated that the first sound beam position 50 a is not specificallylimited to the location shown in FIG. 5, and could be located at anyposition within the interior portion 16. Next, the phased array probe 20can move the sound beam 50. For example, the transmission of the soundbeam 50 from the transducer elements 24 can be delayed (e.g., timeshifted), to form a pattern of constructive interference. Based on thisdelay and time shifting, the sound beam 50 from the inspection surface22 can be moved/guided within the interior portion 16. In particular,the sound beam 50 can be moved along a direction 52, such that the soundbeam 50 will move from the first sound beam position 50 a to a secondsound beam position 50 b.

As the sound beam 50 moves within the test object 12, the sound beam 50can detect the characteristic 18 within the interior portion 16. Inparticular, an echo of the sound beam 50 can reflect off thecharacteristic 18, whereupon the echo is received by the transducerelements 24. Information related to this echo (e.g., amplitude, time offlight, etc.) can be compared with echo signals of known circular diskreflectors. Using a DGS diagram, information related to thecharacteristic 18 is determinable by comparing the echo amplitude withan array of curves of circular disk reflectors recorded in the DGSdiagram. In particular, since the sound beam 50 from either theinspection surface 22 or second inspection surface 122 is rotationallysymmetric, the DGS method can still be used since the DGS method dependson a rotationally symmetric sound field.

It is to be appreciated that the first sound beam position 50 a andsecond sound beam position 50 b are somewhat generically/schematicallyrepresented. Indeed, in further examples, the range along which thesound beam 50 moves is not limited to the range shown in FIG. 5. In oneparticular example, the sound beam 50 can have a range of approximately48°, from +24° to −24° with respect to a perpendicular axis extendingthrough a center of the inspection surface 22. Of course, in otherexamples, the sound beam 50 could have a larger or smaller range. Therange of the sound beam 50 can depend on the size of the transducerelements, such that smaller sized transducer elements allow for a largerrange.

The sound beam 50 in FIG. 5 is shown to move along the direction 52 thatis generally parallel to the axial direction of the test object 12.However, in further examples, rotation of the phased array probe 20 willcause the sound beam 50 to move in other directions that are notparallel to the axial direction of the test object 12. For example, thephased array probe 20 could be rotated 90°, such that the direction 52of the sound beam 50 is substantially transverse to the axial directionof the test object 12. In other examples, the phased array probe 20includes the second inspection surface 122. As such, the sound beam 50is movable along three dimensions.

Turning now to FIG. 6, a second example of an ultrasonic detectionassembly 110 is shown. FIG. 6 depicts a sectional view along line 6-6 ofFIG. 2. In this example, however, the second ultrasonic detectionassembly 110 includes an adjustment structure 112. The test object 12 isgenerally identical to the test object 12 described above with respectto FIGS. 1 to 5. Likewise, the phased array probe 20 is also generallyidentical to the phased array probe 20 described above with respect toFIGS. 1 to 5. As such, the test object 12 and phased array probe 20 willnot be described again with respect to FIG. 6.

The second ultrasonic detection assembly 110 shown in FIG. 6 is asectional view of FIG. 2. However, the second ultrasonic detectionassembly 110 includes the adjustment structure 112 while FIG. 2 does notshow the adjustment structure 112. It is to be appreciated that FIG. 6is similar to FIG. 2, but also includes the adjustment structure 112. Inparticular, for ease of illustration and to more clearly show portionsof the invention, a sectional view of the second ultrasonic detectionassembly 110 is shown to include the adjustment structure 112. Inoperation, the second ultrasonic detection assembly 110 will include theadjustment structure 112 when shown in perspective view.

The second ultrasonic detection assembly 110 includes the adjustmentstructure 112. The adjustment structure 112 functions to improve contactbetween the phased array probe 20 and the test object 12. For example,the adjustment structure 112 includes a first surface 113 and a secondsurface 114. The first surface 113 includes a size and shape thatsubstantially matches a size and shape of the inspection surface 22. Forexample, the first surface 113 has a generally planar shape that matchesthe planar shape of the inspection surface 22. In further examples, thefirst surface 113 could include other, non-planar shapes, that match anon-planar shape of the inspection surface. Indeed, the inspectionsurface could include either of the inspection surface 22 shown in FIG.3 or the second inspection surface 122 shown in FIG. 4, with the firstsurface 113 engaging and contacting either of the inspection surface 22or second inspection surface 122.

The adjustment structure 112 further includes the second surface 114.The second surface 114 has a size and shape that substantially matches asize and shape of the peripheral surface 14 of the test object 12. Forexample, the second surface 114 includes a curved, generally concavesurface that receives and contacts the peripheral surface 14 of the testobject 12. Of course, the second surface 114 is not so limited to theshape shown in FIG. 6. Instead, in further examples, the test object 12could have a larger or smaller diameter than as shown. To accommodatefor this larger or smaller diameter, the second surface 114 could have agreater or lesser degree of concavity, such that the second surface 114will receive the test object 12.

The adjustment structure 112 could include any number of materials. Inone example, the adjustment structure 112 includes an acrylic material,such as polymethyl methacrylate (e.g., Plexiglass®) or the like. Theadjustment structure 112 can be clear or opaque, such that a sound beam150 can pass through the adjustment structure 112.

The phased array probe 20 will transmit the sound beam 150 from theinspection surface 22 and into the test object 12. The sound beam 150can pass through the adjustment structure 112, by entering through thefirst surface 113 and then exiting through the second surface 114. Theadjustment structure 112 can have a certain influence on the sound beam150 due to refraction. In particular, as shown in FIG. 6, the sound beam150 can change directions by passing through the adjustment structure112. The influence on the sound beam 150 by the adjustment structure 112could be larger or smaller than as shown, such that the refraction ofthe sound beam 150 could be more or less severe in further examples.Accordingly, this refraction of the sound beam 150 can be compensatedfor by knowing the characteristics of the adjustment structure 112,including dimensions (thickness, concavity, etc.), type of material,etc. As such, the sound beam 150 can be moved in a similar manner asdescribed above with respect to FIG. 5 while compensating for refractiondue to the adjustment structure 112.

Providing the adjustment structure 112 allows for enhanced coupling ofthe phased array probe 20 and the test object 12. In examples in whichthe test object 12 has a relatively small diameter as compared to a sizeof the inspection surface 22, the adjustment structure 112 is providedto reduce gaps, spaces, etc. between the inspection surface 22 and thetest object 12. Without the adjustment structure 112, these gaps,spaces, etc. may exist at edges of the inspection surface 22. The soundbeam may be distorted or less effective by traveling from the inspectionsurface 22, through the gap, space, etc., and then into the test object12. By including the adjustment structure 112, the sound beam 150 may nolonger need to travel through such gaps, and instead can pass throughthe adjustment structure 112 at positions where the inspection surface22 and peripheral surface 14 are not in contact (or not adjacent eachother).

One example ultrasonic detection assembly includes a phased array probepositioned in proximity to a peripheral surface of the test object, thephased array probe including a plurality of adjacent transducer elementscollectively configured to provide an inspection surface extendingsubstantially parallel to a direction along which the test objectextends, each transducer being operatively configured to emit arespective beam into the test object so as to provide a pattern ofconstructive interference such that the phased array probe is providinga single, rotationally symmetric sound beam into the test object, thephased array probe being configured to provide for a rotational symmetrythat exists over a complete steering range of the phased array probe.

Another example ultrasonic detection assembly includes a phased arrayprobe positioned in proximity to a peripheral surface of the testobject, the phased array probe including a plurality of adjacenttransducer elements collectively configured to provide an inspectionsurface, each transducer being operatively configured to emit arespective beam into the test object so as to provide a pattern ofconstructive interference such that the phased array probe is providinga single, rotationally symmetric sound beam into the test object, thephased array probe being configured to move the sound beam within arange of angles from the phased array probe and bounded by a first beamposition extending in a first direction from the phased array probe anda second beam position extending in a second, different direction fromthe phased array probe within the test object to detect thecharacteristic.

Another example ultrasonic detection assembly includes a phased arrayprobe positioned in proximity to a peripheral surface of the testobject, the phased array probe being configured to transmit a sound beaminto the test object, wherein the sound beam is movable by the phasedarray probe within the test object to detect the characteristic. Thephased array probe includes a plurality of transducer elements that areconfigured to transmit the sound beam, an inspection surface of thetransducer elements configured to extend substantially parallel to adirection along which the test object extends.

The invention has been described with reference to the exampleembodiments described above. Modifications and alterations will occur toothers upon a reading and understanding of this specification. Exampleembodiments incorporating one or more aspects of the invention areintended to include all such modifications and alterations insofar asthey come within the scope of the appended claims.

What is claimed is:
 1. An ultrasonic detection assembly for detecting acharacteristic in a test object, the ultrasonic detection assemblyincluding: a phased array probe positioned in proximity to a peripheralsurface of the test object, the phased array probe including a pluralityof adjacent transducer elements collectively configured to provide aninspection surface extending substantially parallel to a direction alongwhich the test object extends, each transducer being operativelyconfigured to emit a respective beam into the test object so as toprovide a pattern of constructive interference such that the phasedarray probe is providing a single, rotationally symmetric sound beaminto the test object, the phased array probe being configured to providefor a rotational symmetry that exists over a complete steering range ofthe phased array probe.
 2. The ultrasonic detection assembly of claim 1,wherein the phased array probe is configured to retain the rotationalsymmetry while phasing.
 3. The ultrasonic detection assembly of claim 1,wherein the phased array probe is non-movably positioned in proximity tothe peripheral surface of the test object as the sound beam moves. 4.The ultrasonic detection assembly of claim 3, wherein the plurality oftransducer elements are linearly segmented.
 5. The ultrasonic detectionassembly of claim 4, wherein the linearly segmented transducer elementsare configured to generate and transmit the sound beam, the sound beambeing movable along a two dimensional direction within the test object.6. The ultrasonic detection assembly of claim 5, wherein the pluralityof transducer elements are arranged as a matrix.
 7. The ultrasonicdetection assembly of claim 6, wherein the matrix includes an 8×8matrix.
 8. The ultrasonic detection assembly of claim 6, wherein withinthe matrix formed of the plurality of transducer elements, a generallycircular grouping formed from the transducer elements is configured totransmit the sound beam.
 9. The ultrasonic detection assembly of claim8, wherein the generally circular grouping formed from the transducerelements is configured to generate and transmit the sound beam, thesound beam being movable along a three dimensional direction within thetest object.
 10. An ultrasonic detection assembly for detecting acharacteristic in a test object, the ultrasonic detection assemblyincluding: a phased array probe positioned in proximity to a peripheralsurface of the test object, the phased array probe including a pluralityof adjacent transducer elements collectively configured to provide aninspection surface, each transducer being operatively configured to emita respective beam into the test object so as to provide a pattern ofconstructive interference such that the phased array probe is providinga single, rotationally symmetric sound beam into the test object, thephased array probe being configured to move the sound beam within arange of angles from the phased array probe and bounded by a first beamposition extending in a first direction from the phased array probe anda second beam position extending in a second, different direction fromthe phased array probe within the test object to detect thecharacteristic.
 11. The ultrasonic detection assembly of claim 10,wherein the phased array probe includes an adjustment structure locatedinterposed between the test object and the plurality of adjacenttransducer elements to improve contact between the phased array probeand the test object.
 12. The ultrasonic detection assembly of claim 11,wherein the test object has a curved surface and the adjustmentstructure has a complementary curved surface.
 13. An ultrasonicdetection assembly for detecting a characteristic in a test object, theultrasonic detection assembly including: a phased array probe positionedin proximity to a peripheral surface of the test object, the phasedarray probe being configured to transmit a sound beam into the testobject, wherein the sound beam is movable by the phased array probewithin the test object to detect the characteristic; wherein the phasedarray probe includes a plurality of transducer elements that areconfigured to transmit the sound beam, an inspection surface of thetransducer elements configured to extend substantially parallel to adirection along which the test object extends.
 14. The ultrasonicdetection assembly of claim 13, wherein the phased array probe isnon-movably positioned in proximity to the peripheral surface of thetest object as the sound beam moves.
 15. The ultrasonic detectionassembly of claim 14, wherein the plurality of transducer elements arelinearly segmented.
 16. The ultrasonic detection assembly of claim 15,wherein the linearly segmented transducer elements are configured togenerate and transmit the sound beam, the sound beam being movable alonga two dimensional direction within the test object.
 17. The ultrasonicdetection assembly of claim 14, wherein the plurality of transducerelements are arranged as a matrix.
 18. The ultrasonic detection assemblyof claim 17, wherein the matrix includes an 8×8 matrix.
 19. Theultrasonic detection assembly of claim 17, wherein within the matrixformed of the plurality of transducer elements, a generally circulargrouping formed from the transducer elements is configured to transmitthe sound beam.
 20. The ultrasonic detection assembly of claim 19,wherein the generally circular grouping formed from the transducerelements is configured to generate and transmit the sound beam, thesound beam being movable along a three dimensional direction within thetest object.